Alzheimer's disease (AD) is a neurodegenerative disorder of the central nervous system and the leading cause of a progressive dementia in the elderly population. Its clinical symptoms are impairment of memory, cognition, temporal and local orientation, judgment and reasoning but also severe emotional disturbances. There are currently no treatments available which can prevent the disease or its progression or stably reverse its clinical symptoms. AD has become a major health problem in all societies with high life expectancies and also a significant economic burden for their health systems.
The BACE1 enzyme is responsible for one of the proteolytic cleavages of the APP protein that contributes to the generation of the Alzheimer's disease-associated Aβ-peptide. Retarding or stopping the production of Aβ-peptide through inhibition of the BACE1 enzyme is a promising therapeutic concept.
Active site-directed BACE1 inhibitors are described in e.g. WO2006/002907 and exosite-directed (catalytic domain) BACE1 inhibitors are described in e.g. Kornacker et al., Biochemistry 2005, 44, 11567-73.
Bodor et al describe modified peptides suitable to penetrate the blood-brain-barrier (Bodor et al., Science, Vol. 257, 1992).